3. Use of immunomodulators (e.g., interleukins, interferons, cyclosporine), HIV vaccine, systemic cytotoxic chemotherapy, or investigational therapy within 30 days prior to study entry. Chronic treatment with prednisone at a daily dose of 10 mg or less is permitted. For non-serious illnesses, treatment of less than 21 days with larger doses of corticosteroids is permitted.